Method and assembly for securing an implantable medical device on a delivery system

Abstract

A method and an assembly for securing a crimped medical device over a deflated balloon of a balloon catheter is provided. The medical device is positioned in its expanded state over the deflated balloon of the balloon catheter, and is then crimped over the deflated balloon. First and second eyelets of first and second strings, respectively, are then threaded through first and second rings, respectively, that are provided on the medical device. Next, a locking wire is advanced through a lumen defined between the sheath and the catheter body to exit the distal end of the sheath, and then advanced through the first and second eyelets and into the distal tip of the balloon catheter. The sheath is then advanced over the crimped medical device to the distal tip to completely cover the crimped medical device.

What is claimed is: 
     
       1. A delivery system for a medical device, comprising:
 a balloon catheter having a catheter body that has a distal tip, and a balloon provided adjacent to, and proximal to, the distal tip, the balloon having a distal end and a proximal end, the balloon catheter further comprising a first string secured to the balloon catheter at a position adjacent the distal end of the balloon and having a first eyelet, and a second string secured to the balloon catheter at a position adjacent the proximal end of the balloon and having a second eyelet; 
 the medical device having a tubular device body and a radial direction, the medical device having a first end and a second end, with a first ring provided at the first end and a second ring provided at the second end; and 
 the delivery system further comprising a locking wire, wherein when the medical device is crimped over the balloon that is deflated, the first and second eyelets are threaded through the first and second rings, respectively, and the locking wire is located at a radial outside of the medical device and threaded through the first and second eyelets, respectively, with one end of the locking wire being coupled to the distal tip, 
 wherein at least one of the first string and the second string is movable relative to the balloon; and 
 wherein the balloon catheter further comprises a middle sheath movably surrounding the catheter body, with the second string attached to a distal end of the middle sheath. 
 
     
     
       2. The delivery system for a medical device according to  claim 1 , wherein the first string is configured to be threaded outwardly through the first ring from a radial inside of the medical device so that the first eyelet is located at the radial outside of the medical device; and
 the second string is configured to be threaded outwardly through the second ring from the radial inside of the medical device so that the second eyelet is located at the radial outside of the medical device. 
 
     
     
       3. The delivery system for a medical device according to  claim 1 , wherein at least one of the first ring and the second ring is attached to the medical device as an independent ring. 
     
     
       4. The delivery system for a medical device according to  claim 1 , wherein the device body has a plurality of cells, and at least one of the first ring and the second ring is provided as a rounded or enlarged tip of the cell. 
     
     
       5. The delivery system for a medical device according to  claim 1 , wherein the device body has a plurality of cells, and at least one of the first ring and the second ring is provided as an opening in an apex of the cell. 
     
     
       6. The delivery system for a medical device according to  claim 1 , wherein the balloon catheter further comprises a connecting wire that connects the first and second strings. 
     
     
       7. The delivery system for a medical device according to  claim 6 , further comprising a central tubing located within the catheter body and extending through the balloon, the central tubing having a first central lumen and a second lumen that is offset from the first central lumen, and the connecting wire extending through the second lumen, and
 two openings are defined in a lumen wall of the second lumen, with the first and second strings extending out of the central tubing through the respective openings. 
 
     
     
       8. An intervention system, comprising:
 a balloon catheter having a catheter body that has a distal tip, and a balloon provided adjacent to, and proximal to, the distal tip, the balloon having a distal end and a proximal end, the balloon catheter further comprising a first string secured to the balloon catheter at a position adjacent the distal end of the balloon and having a first eyelet, and a second string secured to the balloon catheter at a position adjacent the proximal end of the balloon and having a second eyelet; 
 a heart valve assembly having a generally cylindrical stent body and having a radial direction, with a plurality of leaflets secured inside a lumen of the stent body, and the heart valve assembly having a distal end and a proximal end, with at least one ring provided at the distal end of the heart valve assembly and at least one ring provided at the proximal end of the heart valve assembly; and 
 a locking wire, wherein when the stent body is crimped over the balloon that is deflated, the first and second eyelets are threaded through the rings on the heart valve assembly, respectively, and the locking wire is located at a radial outside of the heart valve assembly and threaded through the first and second eyelets, respectively, with one end of the locking wire being coupled to the distal tip. 
 
     
     
       9. The intervention system according to  claim 8 , wherein the first string is configured to be threaded outwardly through one of the at least one ring at the distal end of the heart valve assembly from a radial inside of the heart valve assembly so that the first eyelet is located at the radial outside of the heart valve assembly; and
 the second string is configured to be threaded outwardly through one of the at least one ring at the proximal end of the heart valve assembly from the radial inside of the heart valve assembly so that the second eyelet is located at the radial outside of the heart valve assembly. 
 
     
     
       10. The intervention system according to  claim 8 , wherein at least one of the rings is movable relative to the balloon. 
     
     
       11. The intervention system according to  claim 10 , wherein the balloon catheter further comprises a middle sheath movably surrounding the catheter body, with the second string attached to a distal end of the middle sheath. 
     
     
       12. The intervention system according to  claim 8 , wherein at least one of the rings is attached to the heart valve assembly as an independent ring. 
     
     
       13. The intervention system according to  claim 8 , wherein the stent body has a plurality of cells, and at least one of the rings is provided as a rounded or enlarged tip of the cell. 
     
     
       14. The intervention system according to  claim 8 , wherein the stent body has a plurality of cells, and at least one of the rings is provided as an opening in an apex of the cell. 
     
     
       15. The intervention system according to  claim 8 , wherein the balloon catheter further comprises a connecting wire that connects the first and second strings. 
     
     
       16. The intervention system according to  claim 15 , further comprising a central tubing located within the catheter body and extending through the balloon, the central tubing having a first central lumen and a second lumen that is offset from the first central lumen, and the connecting wire extending through the second lumen, and
 two openings are defined in a lumen wall of the second lumen, with the first and second strings extending out of the central tubing through the respective openings. 
 
     
     
       17. A method of securing a medical device over a balloon catheter, comprising the steps of:
 providing a balloon catheter having a catheter body that has a distal tip, and a balloon provided adjacent to, and proximal to, the distal tip, the balloon having a distal end and a proximal end, the balloon catheter further comprising a first string secured to the balloon catheter at a position adjacent the distal end of the balloon and having a first eyelet, and a second string secured to the balloon catheter at a position adjacent the proximal end of the balloon and having a second eyelet; 
 wherein the medical device having a tubular device body and a radial direction, the medical device having a first end and a second end, with a first ring provided at the first end and a second ring provided at the second end; 
 providing a locking wire; 
 positioning the medical device in its expanded state over the balloon that is deflated; 
 crimping the medical device over the deflated balloon; 
 threading the first and second eyelets of the first and second strings, respectively, through the first and second rings, respectively; 
 advancing the locking wire through the first and second eyelets at a radial outside of the medical device and into the distal tip; and 
 providing a connecting wire connecting the first string and the second string, and pulling the connecting wire tautly so that the first string and the second string are also pulled taut so that the medical device is restrained over the balloon. 
 
     
     
       18. The method according to  claim 17 , further including:
 outwardly threading the first string through the first ring from a radial inside of the medical device so that the first eyelet is located at the radial outside of the medical device; and 
 outwardly threading the second string through the second ring from the radial inside of the medical device so that the second eyelet is located at the radial outside of the medical device. 
 
     
     
       19. The method according to  claim 17 , further comprising pulling the second string tautly so that the medical device is restrained over the balloon, wherein the second string is movable relative to the balloon.